Index: trunk/src/transform_field/ima_decimate.m
===================================================================
--- trunk/src/transform_field/ima_decimate.m	(revision 958)
+++ trunk/src/transform_field/ima_decimate.m	(revision 958)
@@ -0,0 +1,78 @@
+% 'ima_filter':  low-pass filter of an image followed by decimation 
+
+%------------------------------------------------------------------------
+%%%%  Use the general syntax for transform fields with a single input and parameters %%%%
+% OUTPUT: 
+% DataOut:   output field structure 
+%
+%INPUT:
+% DataIn:  input field structure
+% Param: matlab structure whose field Param.TransformInput contains the filter parameters
+%-----------------------------------
+
+%=======================================================================
+% Copyright 2008-2016, LEGI UMR 5519 / CNRS UGA G-INP, Grenoble, France
+%   http://www.legi.grenoble-inp.fr
+%   Joel.Sommeria - Joel.Sommeria (A) legi.cnrs.fr
+%
+%     This file is part of the toolbox UVMAT.
+%
+%     UVMAT is free software; you can redistribute it and/or modify
+%     it under the terms of the GNU General Public License as published
+%     by the Free Software Foundation; either version 2 of the license,
+%     or (at your option) any later version.
+%
+%     UVMAT is distributed in the hope that it will be useful,
+%     but WITHOUT ANY WARRANTY; without even the implied warranty of
+%     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+%     GNU General Public License (see LICENSE.txt) for more details.
+%=======================================================================
+
+function DataOut=ima_filter(DataIn,Param)
+
+%% request input parameters
+if isfield(DataIn,'Action') && isfield(DataIn.Action,'RUN') && isequal(DataIn.Action.RUN,0)
+    prompt = {'npx';'npy'};
+    dlg_title = 'get the filter size in x and y';
+    num_lines= 2;
+    def     = { '20';'20'};
+    if isfield(Param,'TransformInput')&&isfield(Param.TransformInput,'FilterBoxSize_x')&&...
+            isfield(Param.TransformInput,'FilterBoxSize_y')
+        def={num2str(Param.TransformInput.FilterBoxSize_x);num2str(Param.TransformInput.FilterBoxSize_y)};
+    end
+    answer = inputdlg(prompt,dlg_title,num_lines,def);
+    DataOut.TransformInput.FilterBoxSize_x=str2num(answer{1}); %size of the filtering window
+    DataOut.TransformInput.FilterBoxSize_y=str2num(answer{2}); %size of the filtering window
+    return
+end
+
+DataOut=DataIn; %default
+
+%definition of the cos shape matrix filter
+bx=Param.TransformInput.FilterBoxSize_x;
+by=Param.TransformInput.FilterBoxSize_y;
+ix=1/2-bx/2:-1/2+bx/2;%
+iy=1/2-by/2:-1/2+by/2;%
+%del=np/3;
+%fct=exp(-(ix/del).^2);
+fct2_x=cos(ix/((Param.TransformInput.FilterBoxSize_x-1)/2)*pi/2);
+fct2_y=cos(iy/((Param.TransformInput.FilterBoxSize_y-1)/2)*pi/2);
+%Mfiltre=(ones(5,5)/5^2);
+Mfiltre=fct2_y'*fct2_x;
+Mfiltre=Mfiltre/(sum(sum(Mfiltre)));%normalize filter
+
+Atype=class(DataIn.A);% detect integer 8 or 16 bits
+if numel(size(DataIn.A))==3
+    DataOut.A=filter2(Mfiltre,sum(DataIn.A,3));%filter the input image, after summation on the color component (for color images)
+    DataOut.A=uint16(DataOut.A); %transform to 16 bit images
+else
+    DataOut.A=filter2(Mfiltre,DataIn.A);
+    DataOut.A=feval(Atype,DataOut.A);%transform to the initial image format
+end
+%reduce the size of the image
+[npy,npx]=size(DataOut.A);
+ind_y=ceil(by/2):by:npy-ceil(by/2);
+ind_x=ceil(bx/2):bx:npx-ceil(bx/2);
+B=DataOut.A(ind_y,ind_x);
+DataOut.A=B;
+